[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › Muscarinic antipsychotics

# Muscarinic antipsychotics

Antipsychotics that act through muscarinic M1 and M4 receptors instead of blocking dopamine D2 receptors. The first is xanomeline with trospium.

Updated Nov 1, 2026

## What they are

A new class for schizophrenia. Its central muscarinic agonist is paired with a peripheral antimuscarinic so that the brain receives the muscarinic signal while the gut, glands and bladder are partly protected.

## Mechanism of action

Mice lacking the M4 receptor show a psychosis-like phenotype, which made M4 agonism a candidate antipsychotic mechanism. Xanomeline is an M1- and M4-preferring agonist that acts in the brain. Trospium is a quaternary antimuscarinic that stays mostly outside the brain; it is added to limit xanomeline's cholinergic effects in the rest of the body.

Target: Muscarinic M1 and M4 receptors (central agonist) plus peripheral muscarinic receptors (antagonist)

## Key points

- First antipsychotic approach that does not rely on blocking dopamine D2 receptors.
- Xanomeline (M1/M4 agonist) works in the brain; trospium (quaternary antagonist) works mostly in the periphery.
- Expected side effects are gastrointestinal (nausea, constipation, abdominal pain), dry mouth, fast heart rate and dizziness.
- Urinary retention, glaucoma and liver disease are reasons for caution because of the antimuscarinic part and liver effects.

## Drugs in this class

- [**Xanomeline and trospium** A schizophrenia treatment that stimulates brain M1/M4 muscarinic receptors (xanomeline) while trospium blocks… Muscarinic M4 and M1 receptors (xanomeline, agonist); M4 shown](https://durgical.com/en/pharmacology/xanomeline-and-trospium/)

## Test yourself

Think of the answer, then tap the question to see it.

## Which receptors does xanomeline stimulate?

Muscarinic M1 and M4 receptors.

## Why is trospium combined with xanomeline?

It blocks peripheral muscarinic receptors but barely enters the brain, reducing xanomeline's peripheral cholinergic effects.

## How does this class differ from all earlier antipsychotics?

It does not work by blocking or partially stimulating dopamine D2 receptors.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/classes/muscarinic-antipsychotics/)

[More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology)

[← All of pharmacology](https://durgical.com/en/pharmacology/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [Xanomeline and trospium chloride: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a624070.html) (MedlinePlus (U.S. National Library of Medicine), 2026).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

---
Source: https://durgical.com/en/pharmacology/classes/muscarinic-antipsychotics/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/classes/muscarinic-antipsychotics/